Timing curve for my big-cam 451?

Rat Bastid said

You need to shorten up the curve so it doesn’t pull any timing when it starts. It needs to start on initial and not start adding timing until 500-600 rpm above idle speed. You need to use heavy enough springs to keep the timing from moving around at idle. It should add timing about 1 to maybe 2 degrees per 1k rpm.

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Thanks for actually addressing my question, Rat ;)

Yes, I'm aware of the unstable idle problem that would result from advance starting to come in at idle speed. That's another reason I used the heavy OEM spring.

As I explained, I can't start on initial over 22 without kickback and I do not want to have a separate ignition toggle or a start retard box.... and 22 is not enough idle timing for that cam. It idles much smoother and cleaner at 27... 30 would be even better.

So timing is 27 at 1200 and 35 at 4000. That is +8 degrees in +2800 RPM. You are suggesting I actually run less advance than that? Then I'd need more idle timing around 30-32 and still end up at 35@4000? Not too much for street use?